Back to a previous query from, maybe, yesterday, because it's getting a bit busy wth lots of comments, the distributor can be installed in its offset D at 180 degrees out because I did it myself, in my early ignorance, in back in the '60s..You only make this mistake once.

It was on a Ford Zephyr, which had a similar Lucas distributor, and I'd replaced the oil pump that the distributor drives from. When I discovered the mistake, I just pulled it out, turned it half a turn and all was fine. It can be difficult to see which is the biggest half of the offset drive down the dark hole. When you know about it, yoiu just use a torch to make sure, check and then double-check.

I'd think, from all that's been said, that your distributor just needs pulling out, looking at carefully and re-installing in its correct position. It will pay to also check the the leads are in their correct position in the cap and go to their correct sparking plug. Easy Peasy and a good night's sleep will follow.

Ray

 

Is your car positive or negative ground? Check the wires coming off the coil. If positive ground check that the positive (CB) lead is going to the distributer and the negative (SW) is going to ignition. If they are switched your car won't start and cause some backfiring like you mentioned . If negative ground then the wires are reversed. I know this from experience with an old Dodge that was negative ground and I connected the wires from the coil on the opposite leads. Car backfired through the carburetor singing my brothers eyebrows. Hilarious at the time, his wife didn't think so.

 

I've seen many older cars and bikes with Lucas ignition systems wired up with the wrong polarity, particularly when UK vehicles changed from positive to negative earth between about 1967 and the mid-'70s. After a while the coil may overheat so it's always best for the coil to earth down via the points. I think, with the wrong polarity, the spark will just jump backwards, from the side of the plug to the central electrode. This can cause the coil to get hot and then a misfire may occur if the wires are not re-fitted correctly on the coil. However, I can't see how it would cause a car not to spark or start.

When changing the polarity, usually after updating from dynamo to alternastor, I think the only things to suffer are the clock and the radio.

Ray

 

OK, to answer questions:

• Positive Ground
• I tried to purposely insert the Distributor 180 deg out - will not fit, tried quite hard... will not slot in.

This has become a loud thread, so can i ask for the next steps please?

Here is my understanding - correct me if wrong:

Spark must be on the compression stroke to ignite the fuel air mix - with #1 at TDC on Compression my Distributor is 180 deg out - the rotor arm points at my right knee when standing to the side of the engine bay.

It would seem my valve timing is good, my distributor drive is out by 180 deg?

I understand I have two choices from what I can tell from above comments? -
Take the motor apart and fix the distributor drive OR wire up the Distributor Cap 180 degree out - with #1 being on the opposite terminal (but preserve the firing order) ?

Did I miss anything?

 

I will agree with all what you said, especially this.
Much easier to change the wires on the distributor then taking the engine apart.

Just curious, which way does your rotor turn on your car ?

 

Yes, you just need to refit all the plug leads in the cap so they go to the correct plug when that cylinder is at tdc on its compression stroke.

I'd say, from what you've noted and pictured, they all just need moving round the cap three places. Whichever piston is at the top on its compression stroke needs to have the rotor arm pointing to the correct lead position in the cap. Very straightforward and only ten minutes messing around, I'd think.

Again - 1 5 3 6 2 4 order. It doesn't actually matter where they are in the cap as long as they are in ther correct order and you start off with the first one going to the right cylinder.

Ray

 

Anticlockwise (CCW in american).

 

Thank you, I had removed the leads as they were a bit of a mess - all tangled, so wanted to reroute them properly and in doing so - lost one of the copper split washers, so ordered 6 new.
Once they arrive I will reinstall, in the mean time I will Look at the valve clearance... Ill start a new thread to keep this one on topic.

 

It may be a good idea to mark the leads at both ends for future reference.. I got some little numbered sleeves to put on mine, to replace the varying number of bands of narrow tape, to save tracing each lead up to its cap every time - just to be sure.

Also, if I've lost a little copper washer for the plug lead, I'll just strip more insulation off to bundle the copper core up into a knob and then squash it all in. It's a get-you-home method but will last indefinitely when you're a teenager.

Ray

 

Traveling for past 2 days, but dismayed at developments here. As a victim of too many booby-traps past, and unafraid of the boo's that I am an old dinosaur, I can only condone the gerrymandering of an out-of-phase distributor if the OP . . ..
.

• is able to sleep at night while ignoring the tick-tick of time-bomb ticking (all evidence suggests otherwise);
• is confident that his car/engine will die with him and not bedevil any future owner; (yes, that would keep me awake at night);
• is unable or unwilling to correct the error that has apparently been built into his rebuilt engine (despite being aware how to fix it).

The big deal is that this error, if gerrymandered, will return if you, or subsequent owner ever need to replace the dizzy, cap and leads etc. Yes, I will be hammered for not adopting the easy way out, but I have been subjected to too many of these cobbled-together fixes. Stop a moment and consider the plight of a future distributor cap and leads exchange. Yes, you may bodge a 180 out-of-phase issue now , but it is set like a man-trap ready to impale the next unsuspecting victim. Worse still, it conveys the wrong message to all others who refer to this thread in future,

The first principle is fundamental . . . both the drive to oil pump and dizzy (ignition timing) and camshafts (valve timing) rotate at only half that of the crankshaft. So, as referenced some 40 posts ago, it is vital to set up the engine with dizzy drive slot as depicted with lower timing chain spotted to its marks. At this point, the dizzy rotor must point to #1 HT lead. Only now can the head, with both camshafts set using the setting tool, be offered up, fixed down and camshaft drives be fixed . This will result in #1 valves being on the back of the cam (compression > ignition), while #6 will be on the lobe (exhaust).

The assumption that the lower dizzy drive shaft is somehow fixed to the crankshaft is simply untrue. Our poster with the Zephyr is dead right, Your can easily assemble the helical gear 180 out-of-phase . . . I know, because I once did it (but only once!). Next, the assumption that the dizzy is a solid one piece structure from lower keyed drive to rotor, is an even greater error. It can be easily dismantled and rebuilt with new springs and weights, but so easily rebuilt 180 out of phase.

So, we now have a crankshaft (rotating at say 800rpm), and both dizzy (igniton timing) and camshafts (valve timing) rotating at only 400rpm. But here's the rub . . . are the dizzy and valves in phase such that the #1 spark plug fires when its valves are at the compression / ignition TDC?

If out-of-phase, how can it be fixed? Simple . . . lift the distributor, check the drive slot as per posted images. If correct, good. If 180 out-of-phase, rotate crankshaft 1 rotation to next TDC. Now, refit dizzy and ensure rotor is pointing to #1 HT lead. Please avoid describing it as "pointing to my left knee". Use the dizzy cap and confirm rotor points to #1 HT lead. If so, good, If not, remove dizzy and dismantle / rebuild so rotor does point to #1.

With cam covers removed (as per your pic) verify the #1 valves are on compression > igniton. If not (as we suspect) loosen and unmesh both camshaft drives, lift both camshafts, then rotate 180 first one (loose) camshaft, then the other. Using the camshaft setting tool, fix each down, then refit upper timing chain drives (2 bolts first, rotate engine, then final 2 bolts) then rotate nearly 2 crankshaft revs to regain #1 TDC.

If the car dies with you, be well pleased you have not passed on a time-bomb to your kids (or some other future Jaguar owner). Be proud that you have inspired a legacy of knowledge to future readers of this soooooo long thread of how to do things correctly. Above all, feel warm and fuzzy that you have learned a valuable DIY lesson that moves you from tyro to toreador . . . and best of all, allows you to sleep at night!

Cheers and best wishes,

 

Thanks to some PM advice from @cat_as_trophy I have dissassembled the Distributor and rebuilt it.

We confirmed the Valve and engine timing is correct - the Distributor drive was 180 degrees out, I also fixed some worn wiring.

In my magic box of spares I found a brand new Distributor cap and split washers - so I cleaned the Leads, Labelled them as suggested and wired up the cap.

I cant test yet as I need a hand to do the Valve Clearances, but what I can tell you thus far (one the ones that are already spun lobes out) - is there is NO clearance at all on the couple that are testable.

I will measure and report back - but in the other thread about valve clearances.

Am tempted to throw in the Coil and "try to start" just to see if it will catch.... thoughts? Can you run the motor without Cam Covers?

Heres the Distributor photos

Broken Wire - very messy


New Wire, cleaned everything

Rotor now points to #1

Rotor now points to #1

New Cap, labelled the Leads as suggested

Old Cap - missing the center plunder too

New Cap

Fitted to motor - #1 is marked with the green chalk pen. points in the right direction.

 

Not advisable to run the engine without the cam covers, it will spatter oil everywhere, especially from the timing chain.
Even if you set them in place, the head fills with oil pretty quick and it will run down the outside of the the head and all over the block.

 

Beg to differ - I've often fired up an engine without cam covers, even my S Type, and we're all still all surviving.

Bit of oil splash, which will wash off easily, and it's a lot easier than getting a good seal twice on an expensive cam cover gasket. We do what we have to do but best to keep it a secret.

Ray

 

He may do what he wants.

 

What news, Lord_P?
Perhaps still re-shimming for good valve tappet clearances?
Remember . . . a few thou over (more gap) is OK, but under is NOT.

Cheers and best wishes mate,

 

Morning, sorry for the delay. Life keeps getting in the way.

whilst I wait for a helper to turn the motor for me.m, I added an oz of oil to #5 waited 10 minutes then retested compression.

#1 137.1 psi

#2 141.6 psi

#3 139.7 psi

#4 126.3 psi

#5 was 63 psi now 135 psi

#6 147.2 psi

going to put it back together and see if she will fire up… work schedule allowing

 

I've just checked back in my book and my S Type's comps were all between 130 and 150 psi when I last checked them a couple of years ago - it's done about 10,000 miles since then and runs fine. I presume you've now re-shimmed the tight valve so no damaged seems to have been done.

In my experience, if the shim will still turn, even with a bit of drag, when the clearance is about nil then it's unlikely that a valve or seat will have been damaged.

Ray

 

not touched the shims yet, still on my to do list.

just thought I’d try the oil test - was suggested by the YouTuber JagVet. He’s local to me.

 

I would still advise that you check clearances and re-shim before attempting to start engine. It has to be done at some time anyway, so why not do it first and avoid further distress. You face a very common scenario . . . with grinding and lapping valve seats in a re-build, unless the valve stems are ground also (and on these engines with cam 'buckets' they rarely are), then the tappet clearances always close up.

That said, you have our respect for how life gets in the way, Happens to all of us.

Greetings and best wishes,

 

Yes, I'll second that, - re-shim the tight valves before firing it up again as it's best to stay ahead in the game. They don't take long to damage the faces and seats once there's no running clearance.

Not an easy job, doing the valves. Just getting the head off was no easy task on my S Type when I discovered the radiator and heater box needs to come out and the Far Better Half keeps worrying about her nail varnish.

Ray.